Marantz SR8200 User Manual page 8

Circle Surround is backward compatible, such that surround playback
is possible from any stereo or passive matrix-encoded material.
Five full-bandwidth, discrete channels of information can be extracted
from an enormous library of material not multi-channel encoded.
These sources include many of today's DVDs and laser discs, as well
as most all video tape, VCD, Compact Disc, radio and television
broadcast material.
Circle Surround and the symbol are trademarks of SRS Labs, Inc.
Circle Surround technology is incorporated under license from SRS
Labs, Inc.
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